How to use

IElementTagStructureHandler

in

org.thymeleaf.processor.element

  throw new TemplateProcessingException("Fragment specifications cannot be empty");
final IEngineConfiguration configuration = context.getConfiguration();
    structureHandler.removeElement();
  } else {
    structureHandler.removeBody();
if (context.getTemplateMode() != fragmentModel.getTemplateMode()) {
    structureHandler.replaceWith(stringWriter.toString(), false);
  } else {
    structureHandler.setBody(stringWriter.toString(), false);
structureHandler.setTemplateData(fragmentTemplateData);
    structureHandler.setLocalVariable(fragmentParameterEntry.getKey(), fragmentParameterEntry.getValue());
    structureHandler.replaceWith(model, true);
  } else {
    structureHandler.setBody(model, true);
  structureHandler.replaceWith(fragmentModel, true);
} else {
  structureHandler.setBody(fragmentModel, true);

    EscapedAttributeUtils.unescapeAttribute(context.getTemplateMode(), attribute.getValue());
final IStandardExpressionParser expressionParser = StandardExpressions.getExpressionParser(context.getConfiguration());
  structureHandler.removeAttribute(attributeName);
  return;
  structureHandler.removeAttribute(newAttributeName);
  structureHandler.removeAttribute(attributeName);
} else {
  structureHandler.replaceAttribute(attributeName, newAttributeName, (newAttributeValue == null? "" : newAttributeValue));
if (!e.hasTemplateName()) {
  e.setTemplateName(tag.getTemplateName());
if (!e.hasLineAndCol()) {
  e.setLineAndCol(attribute.getLine(), attribute.getCol());

        context, attributeValue, false /* no parameters without value */);
if (assignations == null) {
  throw new TemplateProcessingException(
      "Could not parse value as attribute assignations: \"" + attributeValue + "\"");
    throw new TemplateProcessingException(
        "Attribute name expression evaluated as null or empty: \"" + leftExpr + "\"");
      structureHandler.setAttribute(newAttributeName, newAttributeName);
    } else {
      structureHandler.removeAttribute(newAttributeName);
        structureHandler.removeAttribute(newAttributeName);
          tag.getAttributeValue(newAttributeName).length() == 0) {
        structureHandler.setAttribute(newAttributeName, newAttributeValue);
      } else {
        String currentValue = tag.getAttributeValue(newAttributeName);
        if (this.modificationType == ModificationType.APPEND) {
          structureHandler.setAttribute(newAttributeName, currentValue + newAttributeValue);
        } else if (this.modificationType == ModificationType.APPEND_WITH_SPACE) {
          structureHandler.setAttribute(newAttributeName, currentValue + ' ' + newAttributeValue);
        } else if (this.modificationType == ModificationType.PREPEND) {
          structureHandler.setAttribute(newAttributeName, newAttributeValue + currentValue);
        } else { // modification type is PREPEND_WITH_SPACE
          structureHandler.setAttribute(newAttributeName, newAttributeValue + ' ' + currentValue);

@Override
protected void doProcess(
    final ITemplateContext context,
    final IProcessableElementTag tag,
    final AttributeName attributeName, final String attributeValue,
    final Object expressionResult,
    final IElementTagStructureHandler structureHandler) {
  if (expressionResult != null) {
    final String resultStr = expressionResult.toString();
    if (VALUE_ALL.equalsIgnoreCase(resultStr)) {
      structureHandler.removeElement();
    } else if (VALUE_TAG.equalsIgnoreCase(resultStr) || VALUE_TAGS.equalsIgnoreCase(resultStr)) {
      structureHandler.removeTags();
    } else if (VALUE_ALL_BUT_FIRST.equalsIgnoreCase(resultStr)) {
      structureHandler.removeAllButFirstChild();
    } else  if (VALUE_BODY.equalsIgnoreCase(resultStr)) {
      structureHandler.removeBody();
    } else if (!VALUE_NONE.equalsIgnoreCase(resultStr)) {
      throw new TemplateProcessingException(
          "Invalid value specified for \"" + attributeName + "\": only 'all', 'tag', 'body', 'none' " +
          "and 'all-but-first' are allowed, but \"" + attributeValue + "\" was specified.");
    }
  }
}

@Override
protected final void doProcess(
    final ITemplateContext context,
    final IProcessableElementTag tag,
    final AttributeName attributeName, final String attributeValue,
    final IElementTagStructureHandler structureHandler) {
  final IStandardExpressionParser expressionParser = StandardExpressions.getExpressionParser(context.getConfiguration());
  final IStandardExpression expression =
      expressionParser.parseExpression(context, attributeValue);
  validateSelectionValue(context, tag, attributeName, attributeValue, expression);
  final Object newSelectionTarget = expression.execute(context);
  final Map<String,Object> additionalLocalVariables =
      computeAdditionalLocalVariables(context, tag, attributeName, attributeValue, expression);
  if (additionalLocalVariables != null && additionalLocalVariables.size() > 0) {
    for (final Map.Entry<String,Object> variableEntry : additionalLocalVariables.entrySet()) {
      structureHandler.setLocalVariable(variableEntry.getKey(), variableEntry.getValue());
    }
  }
  structureHandler.setSelectionTarget(newSelectionTarget);
}

           final BindStatus bindStatus, final IElementTagStructureHandler structureHandler) {
String name = bindStatus.getExpression();
name = (name == null? "" : name);
boolean checked = false;
Object boundValue = bindStatus.getValue();
final Class<?> valueType = bindStatus.getValueType();
    throw new TemplateProcessingException(
        "Attribute \"value\" is required in \"input(checkbox)\" tags " +
        "when binding to non-boolean values");
  checked = SelectedValueComparatorWrapper.isSelected(bindStatus, HtmlEscape.unescapeHtml(value));
  StandardProcessorUtils.setAttribute(structureHandler, this.checkedAttributeDefinition, CHECKED_ATTR_NAME, CHECKED_ATTR_NAME);
} else {
  structureHandler.removeAttribute(this.checkedAttributeDefinition.getAttributeName());
  final IModelFactory modelFactory = context.getModelFactory();
    structureHandler.insertBefore(hiddenTagModel);
  } else {
    structureHandler.insertImmediatelyAfter(hiddenTagModel, false);

@Override
protected void doProcess(
    final ITemplateContext context, final IProcessableElementTag tag,
    final AttributeName attributeName, final String attributeValue,
    final IElementTagStructureHandler structureHandler) {
  final BindStatus bindStatus = FieldUtils.getBindStatus(context, attributeValue);
  if (bindStatus.isError()) {
    final StringBuilder strBuilder = new StringBuilder();
    final String[] errorMsgs = bindStatus.getErrorMessages();
    for (int i = 0; i < errorMsgs.length; i++) {
      if (i > 0) {
        strBuilder.append(ERROR_DELIMITER);
      }
      final String displayString = ValueFormatterWrapper.getDisplayString(errorMsgs[i], false);
      strBuilder.append(displayString);
    }
    structureHandler.setBody(strBuilder.toString(), false);
    // Just in case we also have a th:errorclass in this tag
    structureHandler.setLocalVariable(SpringContextVariableNames.SPRING_FIELD_BIND_STATUS, bindStatus);
  } else {
    structureHandler.removeElement();
  }
}

@Override
protected void doProcess(final ITemplateContext context,
             final IProcessableElementTag tag,
             final AttributeName attributeName, final String attributeValue,
             final BindStatus bindStatus, final IElementTagStructureHandler structureHandler) {
  String name = bindStatus.getExpression();
  name = (name == null? "" : name);
  final String value = tag.getAttributeValue(this.valueAttributeDefinition.getAttributeName());
  if (value == null) {
    throw new TemplateProcessingException(
        "Attribute \"value\" is required in \"option\" tags");
  }
  final boolean selected =
      SelectedValueComparatorWrapper.isSelected(bindStatus, HtmlEscape.unescapeHtml(value));
  StandardProcessorUtils.setAttribute(
      structureHandler,
      this.valueAttributeDefinition, VALUE_ATTR_NAME,
      RequestDataValueProcessorUtils.processFormFieldValue(context, name, value, "option"));
  if (selected) {
    StandardProcessorUtils.setAttribute(structureHandler, this.selectedAttributeDefinition, SELECTED_ATTR_NAME, SELECTED_ATTR_NAME);
  } else {
    structureHandler.removeAttribute(this.selectedAttributeDefinition.getAttributeName());
  }
}

@Override
protected void doProcess(
    final ITemplateContext context,
    final IProcessableElementTag tag,
    final IElementTagStructureHandler structureHandler) {
  final AttributeName selectAttrNameToAdd =
      (AttributeName) context.getVariable(SpringSelectFieldTagProcessor.OPTION_IN_SELECT_ATTR_NAME);
  if (selectAttrNameToAdd == null) {
    // Nothing to do
    return;
  }
  // It seems this <option> is inside a <select th:field="...">, and the processor for that "th:field" has left
  // as a local variable the name and value of the attribute to be added
  final String selectAttrValueToAdd =
      (String) context.getVariable(SpringSelectFieldTagProcessor.OPTION_IN_SELECT_ATTR_VALUE);
  if (tag.hasAttribute(selectAttrNameToAdd)) {
    if (!selectAttrValueToAdd.equals(tag.getAttributeValue(selectAttrNameToAdd))) {
      throw new TemplateProcessingException(
          "If specified (which is not required), attribute \"" + selectAttrNameToAdd + "\" in " +
          "\"option\" tag must have exactly the same value as in its containing \"select\" tag");
    }
  }
  // This attribute value does not need to be escaped, because we are just "transporting" the th:field in the
  // container <select> to its <option>'s, without any modifications. It will be executed (and its results
  // escaped) later...
  structureHandler.setAttribute(selectAttrNameToAdd.getCompleteAttributeNames()[0], selectAttrValueToAdd);
}

  final IElementTagStructureHandler structureHandler) {
final String newAttributeValue = HtmlEscape.escapeHtml4Xml(expressionResult == null ? null : expressionResult.toString());
  structureHandler.removeAttribute(this.targetAttributeDefinition.getAttributeName());
  structureHandler.removeAttribute(attributeName);
} else {
  StandardProcessorUtils.replaceAttribute(structureHandler, attributeName, this.targetAttributeDefinition, TARGET_ATTR_NAME, newAttributeValue);
    final IModelFactory modelFactory = context.getModelFactory();
    structureHandler.insertImmediatelyAfter(hiddenMethodModel, false);

  EscapedAttributeUtils.unescapeAttribute(context.getTemplateMode(), tag.getAttributeValue(attributeName));
structureHandler.removeAttribute(attributeName);
if (!e.hasTemplateName()) {
  e.setTemplateName(tag.getTemplateName());
if (!e.hasLineAndCol()) {
  if (attributeName == null) {

@Override
protected void doProcess(final ITemplateContext context,
             final IProcessableElementTag tag,
             final AttributeName attributeName, final String attributeValue,
             final IThymeleafBindStatus bindStatus, final IElementTagStructureHandler structureHandler) {
  String name = bindStatus.getExpression();
  name = (name == null? "" : name);
  final String value = tag.getAttributeValue(this.valueAttributeDefinition.getAttributeName());
  if (value == null) {
    throw new TemplateProcessingException(
        "Attribute \"value\" is required in \"option\" tags");
  }
  final boolean selected =
      SpringSelectedValueComparator.isSelected(bindStatus, HtmlEscape.unescapeHtml(value));
  StandardProcessorUtils.setAttribute(
      structureHandler,
      this.valueAttributeDefinition, VALUE_ATTR_NAME,
      RequestDataValueProcessorUtils.processFormFieldValue(context, name, value, "option"));
  if (selected) {
    StandardProcessorUtils.setAttribute(structureHandler, this.selectedAttributeDefinition, SELECTED_ATTR_NAME, SELECTED_ATTR_NAME);
  } else {
    structureHandler.removeAttribute(this.selectedAttributeDefinition.getAttributeName());
  }
}

    throw new TemplateProcessingException(
        "Attribute \"value\" is required in \"input(checkbox)\" tags " +
        "when binding to non-boolean values");
  checked = SpringSelectedValueComparator.isSelected(bindStatus, HtmlEscape.unescapeHtml(value));
  StandardProcessorUtils.setAttribute(structureHandler, this.checkedAttributeDefinition, CHECKED_ATTR_NAME, CHECKED_ATTR_NAME);
} else {
  structureHandler.removeAttribute(this.checkedAttributeDefinition.getAttributeName());
  final IModelFactory modelFactory = context.getModelFactory();
    structureHandler.insertBefore(hiddenTagModel);
  } else {
    structureHandler.insertImmediatelyAfter(hiddenTagModel, false);

           final BindStatus bindStatus, final IElementTagStructureHandler structureHandler) {
String name = bindStatus.getExpression();
name = (name == null? "" : name);
StandardProcessorUtils.setAttribute(structureHandler, this.nameAttributeDefinition, NAME_ATTR_NAME, name); // No need to escape: this is a java-valid token
structureHandler.setLocalVariable(OPTION_IN_SELECT_ATTR_NAME, attributeName);
structureHandler.setLocalVariable(OPTION_IN_SELECT_ATTR_VALUE, attributeValue);
  final IModelFactory modelFactory = context.getModelFactory();
  structureHandler.insertBefore(hiddenMethodElementModel);

  final IElementTagStructureHandler structureHandler) {
String newAttributeValue = HtmlEscape.escapeHtml4Xml(expressionResult == null ? "" : expressionResult.toString());
    final IModelFactory modelFactory = context.getModelFactory();
    structureHandler.insertImmediatelyAfter(extraHiddenElementTags, false);

@Override
protected void doProcess(final ITemplateContext context,
             final IProcessableElementTag tag,
             final AttributeName attributeName, final String attributeValue,
             final BindStatus bindStatus, final IElementTagStructureHandler structureHandler) {
  String name = bindStatus.getExpression();
  name = (name == null? "" : name);
  final String id = computeId(context, tag, name, false);
  final String value = ValueFormatterWrapper.getDisplayString(bindStatus.getValue(), bindStatus.getEditor(), true);
  String processedValue =
      RequestDataValueProcessorUtils.processFormFieldValue(context, name, value, "textarea");
  if (!StringUtils.isEmpty(processedValue)) {
    final char c0 = processedValue.charAt(0);
    if (c0 == '\n') {
      processedValue = '\n' + processedValue;
    } else if (c0 == '\r' && processedValue.length() > 1 && processedValue.charAt(1) == '\n') {
      processedValue = "\r\n" + processedValue;
    } else if (c0 == '\r') {
      processedValue = '\r' + processedValue;
    }
  }
  StandardProcessorUtils.setAttribute(structureHandler, this.idAttributeDefinition, ID_ATTR_NAME, id); // No need to escape: this comes from an existing 'id' or from a token
  StandardProcessorUtils.setAttribute(structureHandler, this.nameAttributeDefinition, NAME_ATTR_NAME, name); // No need to escape: this is a java-valid token
  structureHandler.setBody((processedValue == null? "" : processedValue), false);
}

  final IElementTagStructureHandler structureHandler) {
final IEngineConfiguration configuration = context.getConfiguration();
    structureHandler.removeBody();
    return;
  structureHandler.setBody(((Fragment)expressionResult).getTemplateModel(), false);
  return;
  structureHandler.setBody(unescapedTextStr, false);
  return;
  structureHandler.setBody(unescapedTextStr, false);
  return;
        context.getTemplateData(),
        unescapedTextStr,
        0, 0, // we won't apply offset here because the inserted text does not really come from the template itself
structureHandler.setBody(parsedFragment, false);

      text = new LazyEscapingCharSequence(context.getConfiguration(), templateMode, input);
    } else {
  text = new LazyEscapingCharSequence(context.getConfiguration(), templateMode, expressionResult);
structureHandler.setBody(text, false);

@Override
protected void doProcess(ITemplateContext context, IProcessableElementTag tag, AttributeName attributeName,
    String attributeValue, IElementTagStructureHandler structureHandler) {
  Locale locale = context.getLocale();
  loadSelectorValues(locale);
  String selectorStyle = String.valueOf(attributeValue).trim();
  String messageKey = getMessageKey(selectorStyle);
  String options = composeSelectorOptions(selectorStyle, context);
  String message = Messages.getMessage(BUNDLE_NAME, messageKey, locale, options);
  structureHandler.setBody(message, false);
}

@Override
protected void doProcess(
    final ITemplateContext context, final IProcessableElementTag tag,
    final AttributeName attributeName, final String attributeValue,
    final IElementTagStructureHandler structureHandler) {
  final IThymeleafBindStatus bindStatus = FieldUtils.getBindStatus(context, attributeValue);
  if (bindStatus.isError()) {
    final StringBuilder strBuilder = new StringBuilder();
    final String[] errorMsgs = bindStatus.getErrorMessages();
    for (int i = 0; i < errorMsgs.length; i++) {
      if (i > 0) {
        strBuilder.append(ERROR_DELIMITER);
      }
      final String displayString = SpringValueFormatter.getDisplayString(errorMsgs[i], false);
      strBuilder.append(HtmlEscape.escapeHtml4Xml(displayString));
    }
    structureHandler.setBody(strBuilder.toString(), false);
    // Just in case we also have a th:errorclass in this tag
    structureHandler.setLocalVariable(SpringContextVariableNames.THYMELEAF_FIELD_BIND_STATUS, bindStatus);
  } else {
    structureHandler.removeElement();
  }
}